1. Field of the Invention
The present invention is related to a splash lubricated over head valve engine which is improved to minimize overall height of the engine and to obtain better lubrication of valve driving members such as rocker arms.
The engine according to the present invention is provided with the premise structure; i.e., as shown in the drawings 1 and 2, the splash lubricated over head valve engine according to the present invention is provided with a gas induction passage 4 and an oil return passage 5 both of which communicate a crank room 1 with a rocker arm chamber 3 in a head cover 2 in parallel. The head cover 2 is provided with a breather 6 which inlet 7 is communicated with the rocker arm chamber 3.
2. Description of the Prior Art
In the splash lubricated over head valve engine of the known type, lubricant is fed by means of reciprocation of push rods from the crank room to the rocker arm chamber. In this manner, the strength of feeding pressure is determined by the stroke of the push rods. Therefore, it is impossible to obtain sufficiently high feeding pressure. Moreover, the limitation in the location of the opening for spout in the rocker arm chamber results in the difficulty of the sure feeding of the lubricant to the moving parts of the valve drive mechanism.
In order to avoid these problems, a breather, which serves to dispose of blow-by gas leaked from the combustion chamber to the crankroom, is disposed in the space specially provided on the rocker arm chamber so as to induce blow-by gas into the rocker arm chamber for the separation of the oil therefrom. However, in this known manner, the breather is extruded over the head cover, so that the overall height of the engine is tall disadvantageously.